1. Field of the Invention
The invention relates generally to automatic clothes dryers having separately driven drum and blower
2. Description of the Related Art
Automatic clothes dryers are well known, and typically comprise, a cabinet enclosing a horizontally rotating drum for holding items to be dried and accessible through an access door at the front of the cabinet. The drum is rotated by a belt which is driven by a motor. The motor also drives a blower assembly which delivers dry, heated or unheated air to the drum for drying the items, and exhausts humid air from the drum to a discharge location exterior of the cabinet. The motor and blower assembly are typically mounted in a lower portion of the cabinet beneath the drum. The drum has a first diameter which is ideally maximized within the dimensions of the dryer cabinet. The blower assembly typically utilizes a horizontally rotating fan, having a second, smaller diameter, which must fit within the remaining dryer cabinet space not occupied by the drum. This frequently limits either the size of the drum or the size of the fan, or both.
Dryer cabinets are typically dimensioned to occupy a predetermined sized space, height, width, and depth, in a laundry room or basement area. This simplifies the construction of laundry rooms and any cabinetry. However, a preselected dimension necessarily limits the cabinet interior space available for enclosing the drum, the motor, and the blower assembly. This is a disadvantage in that there is a growing demand for larger capacity dryers.
The capacity of a conventional dryer is further limited in that conventional dryers use a single-shaft, dual-drive motor for driving both the drum and the blower. One end of the shaft is provided with a pulley for driving the belt rotating the drum. The other end of the shaft is directly coupled to the shaft of the blower impeller. The combined mounting of the drum drive and the blower limits where the motor can be mounted within the cabinet as the drum drive needs to be located such that the belt can connect to the drum, with the result that the motor is often located in such a position that the diameter of the drum cannot be maximized within the cabinet in order to accommodate the motor, drum drive, and blower housing.
The coupling of the blower impeller directly to the motor shaft while mechanically convenient is disadvantageous in that it requires the air flow path through the dryer to have additional paths or bends, which slow down the air flow and increase the back pressure in the system. Specifically, the longitudinal axis of the blower is oriented either coaxially or in parallel with the longitudinal axis of the motor. This configuration requires a relatively large space for the blower and motor. This also typically results in a blower exhaust opening which is oriented 90° to the dryer exhaust vent, thereby requiring a 90° elbow between the blower exhaust opening and the dryer exhaust vent.
There is an increasing need in the household dryer market for a dryer with a larger drum capacity for drying larger loads, thereby minimizing the number of separate loads that must be dried, and drying heavy, bulky items such as comforters, rugs, and the like. This need continues to increase as washers are able to achieve larger capacities. Conventional dryer configurations have reached their capacity limits. A new dryer configuration is needed.